During the initial spoiler, I thought Saturn was taken by the Blackbeard Pirates. Seems like he's still staying and still among those that are to be beaten. My guess here is that while Luffy will fight Kizaru, the rest of the Straw Hats especially those with families that were directly attacked by the WG like Franky, Robin, Bonney and Sanji would team up against Saturn. On the other hand, the Pacifistas and the Giants will deal with the Buster Call, while Zoro will deal with Lucci.